Streptococcal toxic shock syndrome
Streptococcal toxic shock syndrome is shock with multiorgan failure caused by superantigen exotoxin from invasive group A Streptococcus, usually arising from a skin or soft tissue infection such as necrotizing fasciitis in a previously healthy adult. It is defined by isolation of group A Streptococcus plus systolic pressure below 90 mm Hg and two or more organ findings, and is treated with resuscitation, emergent surgical debridement, and high-dose penicillin G plus clindamycin; mortality is about 30%.
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What this article covers
- Overview
Toxin-driven shock from invasive group A Streptococcus: streptococcal toxic shock syndrome (TSS) is hypotension with multiorgan failure caused by streptococcal pyrogenic exotoxin A acting as a…
- Epidemiology
Case fatality is about 30%: mortality exceeds 30% in some series and is several times the 5% to 10% of staphylococcal TSS.
- Risk factors
Breaks in the skin from major or minor trauma, particularly penetrating trauma, which give group A Streptococcus entry to the fascia.
- Pathophysiology
Superantigen exotoxin: strains carrying a lysogenic bacteriophage that encodes streptococcal pyrogenic exotoxin A (SpeA) produce a superantigen with the same mechanism as staphylococcal TSST-1.
- Clinical features
Severe pain out of proportion to the skin findings: the earliest and most important clue, at a site of soft tissue infection; some patients present with severe limb pain and no skin lesion at all.
- Differential diagnosis
Staphylococcal toxic shock syndrome: tampon, nasal packing, or wound source with a mandatory diffuse desquamating rash and usually negative blood cultures.
- Diagnosis
Diagnosis is established by the streptococcal TSS case definition: a definite case requires isolation of group A beta-hemolytic Streptococcus (GABHS) from a normally sterile site (blood…
- Management
First, resuscitate with balanced crystalloid 30 mL/kg IV over the first 3 hours, then give further boluses guided by dynamic measures of fluid responsiveness.
- Complications
Death from refractory shock and multiorgan failure: the outcome in about 30% of patients.
- Prognosis
Mortality is about 30%, with some series above 30% despite treatment.
- Prevention
Treat confirmed group A streptococcal pharyngitis: amoxicillin 50 mg/kg PO once daily (maximum 1000 mg) for 10 days, since toxic shock is a recognized complication of streptococcal pharyngitis.
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Related articles
- Necrotizing fasciitis
Necrotizing fasciitis is a rapidly progressive, life-threatening infection of the subcutaneous tissue and superficial fascia driven by vessel thrombosis and bacterial exotoxin production. The hallmark is pain out of proportion to visible skin findings, with crepitus, bullae, and woody induration in advanced disease. Diagnosis is confirmed by direct surgical exploration; the LRINEC score aids risk stratification. Treatment is emergent surgical debridement combined with broad-spectrum empiric antibiotics.
- Staphylococcal toxic shock syndrome
Staphylococcal toxic shock syndrome is a multisystem, toxin-mediated illness caused by TSST-1-producing Staphylococcus aureus acting as a superantigen, classically linked to prolonged tampon use, nasal packing, or a focal staphylococcal infection, diagnosed by a clinical case definition of fever, hypotension, diffuse desquamating rash, and involvement of three or more organ systems, and treated with source control plus antistaphylococcal antibiotics including clindamycin.
- Septic shock
Septic shock is the subset of sepsis with hypotension requiring vasopressors to maintain a mean arterial pressure above 65 mm Hg plus a serum lactate above 2 mmol/L despite adequate fluid resuscitation, carrying in-hospital mortality of 40% or higher. Management is a timed sequence: 30 mL/kg crystalloid bolus, blood cultures and broad-spectrum antibiotics within 1 hour, norepinephrine titrated to MAP >=65, and escalation to a second vasopressor and stress-dose hydrocortisone when hypotension persists.
- Cellulitis
Cellulitis is a nonpurulent, spreading infection of the deep dermis and subcutaneous fat, usually caused by beta-hemolytic streptococci, diagnosed clinically and treated with antibiotics alone since there is no collection to drain.
- Clostridial myonecrosis (gas gangrene)
Clostridial myonecrosis is a fulminant, toxin-mediated necrotizing infection of skeletal muscle, most often from Clostridium perfringens, presenting with pain out of proportion, bullae, and gas in the tissue. Diagnosis is confirmed at surgery. Treatment is emergent surgical debridement plus penicillin and clindamycin.
- Bacteremia
Bacteremia is the presence of viable bacteria in the blood, confirmed by positive blood cultures, that ranges from transient and clinically silent to the trigger for sepsis and septic shock requiring urgent source identification and antimicrobial therapy.
- Streptococcal pharyngitis
Streptococcal pharyngitis is an acute infection of the tonsils and pharynx caused by group A Streptococcus pyogenes, presenting with rapid-onset sore throat, fever, tonsillar exudates, and tender anterior cervical lymphadenopathy without cough; diagnosis relies on the Centor criteria to guide rapid antigen testing, and treatment with penicillin or amoxicillin prevents suppurative complications and acute rheumatic fever.